Fluid dynamic bearing

Abstract

The invention relates to a fluid dynamic bearing system having a stationary bearing component and a moving bearing component, that are separated from one another by a bearing gap filled with a bearing fluid. There are two radial bearing regions separated from one another and marked by radial bearing grooves. A separator region having a larger bearing gap width is disposed between the radial bearing regions. The radial bearing grooves of the two radial bearing regions have inner ends facing each other and outer ends facing away from each other. At least the outer ends of the radial bearing grooves are connected to each other by connecting grooves. According to the invention, wear zones provided especially for this purpose are disposed adjoining the connecting grooves, so as to prevent material wear at other regions of the bearing.

1. A fluid dynamic bearing system having a stationary bearing component ( 12 ;  22 ) and a moving bearing component ( 14 ;  20 ) that are separated from one another by a bearing gap ( 18 ) filled with a bearing fluid and disposed rotatably with respect to one another about a rotational axis ( 48 ), wherein two radial bearing regions ( 24 ;  26 ) separated axially from one another and marked by radial bearing grooves ( 25 ;  27 ) are provided, wherein a separator region ( 29 ) having a larger bearing gap width is located between the radial bearing regions ( 24 ;  26 ) and wherein the radial bearing grooves ( 25 ;  27 ) of the two radial bearing regions ( 24 ;  26 ) have inner ends facing each other and outer ends facing away from each other, and at least the outer ends of the radial bearing grooves ( 25 ;  27 ) are connected to each other by connecting grooves ( 34 ;  36 ), wherein wear zones ( 38 ;  40 ) are provided adjoining the connecting grooves ( 34 ;  36 ). 
     
     
       2. A fluid dynamic bearing system according to  claim 1 , characterized in that the wear zones ( 38 ;  40 ) lie on the same level as the bearing surfaces of the radial bearing regions ( 24 ;  26 ). 
     
     
       3. A fluid dynamic bearing system according to  claim 1 , characterized in that the depth of the connecting grooves ( 34 ;  36 ) approximately corresponds to the depth of the radial bearing grooves ( 25 ;  27 ). 
     
     
       4. A fluid dynamic bearing system according to  claim 1 , characterized in that the depth of the radial bearing grooves ( 25 ;  27 ) and the connecting grooves ( 34 ;  36 ) is approximately 6+/−2 micrometers. 
     
     
       5. A fluid dynamic bearing system according to  claim 1 , characterized in that the wear zones ( 38 ;  40 ) are wider than the respective adjoining connecting grooves ( 34 ;  36 ). 
     
     
       6. A fluid dynamic bearing system according to  claim 1 , characterized in that the width of the connecting grooves ( 34 ;  36 ) is approximately 0.1 mm. 
     
     
       7. A fluid dynamic bearing system according to  claim 1 , characterized in that the width of the wear zones ( 38 ;  40 ) is approximately 0.25 mm. 
     
     
       8. A fluid dynamic bearing system according to  claim 1 , characterized in that the surfaces of the wear zones ( 38 ;  40 ) is provided with a coating. 
     
     
       9. A fluid dynamic bearing system according to  claim 8 , characterized in that the coating of the wear zones ( 38 ;  40 ) is a DLC (diamond-like carbon) coating or a nickel coating or an NFC (near frictionless carbon) coating. 
     
     
       10. A fluid dynamic bearing system according to  claim 1 , characterized in that the stationary bearing component comprises a bearing bush ( 12 ) and a covering cap ( 22 ), and the moving bearing component comprises a shaft ( 14 ) and a thrust plate ( 20 ), the shaft ( 14 ) and the thrust plate ( 20 ) being rotatably disposed in a bearing bore ( 13 ) in the bearing bush ( 12 ). 
     
     
       11. A fluid dynamic bearing system according to  claim 10 , characterized in that the radial bearing grooves ( 25 ;  27 ), the connecting grooves ( 34 ;  36 ) and the wear zones ( 38 ;  40 ) are disposed on the bearing bush ( 12 ). 
     
     
       12. A fluid dynamic bearing system according to  claim 11 , characterized in that the surface of the bearing bore ( 13 ) in the bearing bush ( 12 ) is given a full coating or at least coated in the region of the wear zones ( 38 ;  40 ). 
     
     
       13. A fluid dynamic bearing system according to  claim 10 , characterized in that an axial bearing region ( 28 ) is formed between the thrust plate ( 20 ) and the bearing bush ( 12 ) and/or an axial bearing region ( 30 ) is formed between the thrust plate ( 20 ) and the covering cap ( 22 ). 
     
     
       14. A fluid dynamic bearing system according to  claim 10 , characterized in that the diameter of the shaft ( 14 ) is between 3 and 4 mm. 
     
     
       15. A fluid dynamic bearing system according to  claim 10 , characterized in that the thrust plate ( 20 ) is integrally formed with the shaft ( 14 ) as one piece. 
     
     
       16. A fluid dynamic bearing system according to  claim 10 , characterized in that the thrust plate ( 20 ) has at least one hole ( 42 ) extending approximately parallel to the rotational axis ( 48 ), and that the thrust plate ( 20 ) has a recess ( 50 ) in the exit region of the hole ( 42 ). 
     
     
       17. A fluid dynamic bearing system according to  claim 1 , characterized in that the surface of the shaft ( 14 ) is given a full coating or at least coated in the region lying opposite the wear zones ( 38 ;  40 ). 
     
     
       18. A fluid dynamic bearing system according to  claim 1 , characterized in that at least one recirculation channel ( 43 ) is disposed in the moving bearing component ( 14 ;  20 ), the recirculation channel ( 43 ) connecting the region of the lower end face of the moving bearing component to the separator region ( 29 ). 
     
     
       19. A fluid dynamic bearing system according to  claim 18 , characterized in that the recirculation channel ( 43 ) in the moving bearing component ( 14 ;  20 ) extends obliquely to the rotational axis ( 48 ). 
     
     
       20. A spindle motor having a stator and a rotor and a fluid dynamic bearing system for the rotatable support of the rotor ( 16 ), and an electromagnetic drive system ( 44 ;  46 ), wherein the fluid dynamic bearing system comprises a stationary bearing component ( 12 ;  22 ) and a moving bearing component ( 14 ;  20 ) that are separated from one another by a bearing gap ( 18 ) filled with a bearing fluid and disposed rotatably with respect to each other about a rotational axis ( 48 ), wherein two radial bearing regions ( 24 ;  26 ) separated axially from one another and marked by radial bearing grooves ( 25 ;  27 ) are provided, wherein a separator region ( 29 ) having a larger bearing gap width is located between the radial bearing regions ( 24 ;  26 ) and wherein the radial bearing grooves ( 25 ;  27 ) of the two radial bearing regions ( 24 ;  26 ) have inner ends facing each other and outer ends facing away from each other, and at least the outer ends of the radial bearing grooves ( 25 ;  27 ) are connected to each other by connecting grooves ( 34 ;  36 ), wherein wear zones ( 38 ;  40 ) are provided adjoining the connecting grooves ( 34 ;  36 ).